Determine the students' median weight from the following data.

Weight (in Kg)	<45	<50	<55	<60	<65	<70	<75
No. of Students	2	5	13	19	25	28	30

To calculate the median from the following interval data, we must first compute the cumulative frequencies.

Because the class widths are unequal in this case, we don't need to adjust the interval frequencies.

We have on the x-axis = the weight of students and on the y-axis= number of students.

$N=30$ then $\frac{30}{2}=15$, 

The cumulative frequency just greater than $\frac{n}{2}$​ is 19 and the corresponding class is 55–60.

Thus, 55–60 is the median class such that

$\frac{n}{2}$=15,l=55,f=6,cf=13 , and h=5

Substituting these values in the formula

Median, $M=l+\left(\frac{{\displaystyle \frac{n}{2}}-cf}{f}\right)\times h$

$M=55+(\frac{15-13}{6})\times 5$

M=$55+\frac{2}{6}\times 5=55+1.67=56.67$

 Median $=56.67$